Rook
Power User
I suspect that in order to minimise switching time and [many] other overheads... it isn't a case of 'oh, this newly selected preset uses a flanger, I'll create an instance of a flanger object' but rather that he instantiates all of the allowed instances of all the allowed block types in memory at power on and simply* switches the internal virtual wiring per preset. IOW, volatile memory constraints.
I have wondered the same thing as the OP, and now I have a very reasonable and sensible answer (confirmed by Cliff, no less). Hooray for the forum!